Analysis of the impacts of geomorphological disturbance on alpine and polar vegetation.

• Main Author: Ponti, Stefano
• Other Authors: CANNONE, NICOLETTA, GUGLIELMIN, MAURO
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Università degli Studi dell'Insubria 2018
• Subjects: Vegetation; surfical displacement; rock glacier; permafrost; GEO/04 GEOGRAFIA FISICA E GEOMORFOLOGIA; Arctic; Svalbard; Active layer monitoring; Active layer thickness; Antarc*; Antarctica; Climate change; glacier; Ice; ice core; Tundra
• Online Access: http://hdl.handle.net/11383/2090205; http://hdl.handle.net/10277/794

Under a context of climate change, polar and alpine regions have been demonstrated to be highly susceptible to climatic factors in various scientific fields. One aspect of susceptibility is treated in this thesis in terms of biogeomorphology, in particular for those geomorphic processes that couple the surficial displacements with the vegetation distribution. For these reasons, 3 study areas have been selected in polar (Svalbard and Antarctica) and alpine (Central Alps) regions to carry out this project. The methods used are different depending on the scale and the location of the target. On the Alps, at large scale, surface and climatic data have been used to produce thematic maps useful for a surface dynamic prediction model, while at landform scale, various system have been chosen to observe surface displacements (e.g., painted lines, height-o-meter) in relation to the vegetation distribution (vegetational relevé, line intercept). To quantify small-scale processes, a close-range photogrammetric application has been developed to produce detailed digital elevation models (DEMs) at a millimetric resolution. In the Arctic, ground thermistors and a time-lapse camera were set on a circumpolar active layer monitoring (CALM) grid to assess relationships among ground surface temperature (GST), snow distribution and active layer thickness (ALT) at a sub-metric scale. For understanding the effect of thaw depth on the CO2 fluxes on an arctic tundra environment, an infra-red gas analyzer (IRGA) system was coupled with a frost probing survey on different vegetation communities. In Antarctica, ground penetrating radar (GPR) with electrical resistivity tomography (ERT) have been utilized to detect ice content in 2 rock glaciers and an ice-core stratigraphy validated the digital findings. The results of this project demonstrate that a novel prediction model that take in consideration both surface and climatic data (in particular snow distribution/persistence) to quantify mountainous surface displacement is possible. In ...